In a combustion chamber of a turbomachine, a combustion reaction occurs between the fuel and the oxygen of the air. This results in the hot gas produced by the combustion being expelled at high speed, which gas delivers thrust on expanding. It is this thrust that serves, for example, to propel an airplane fitted with one or more turbomachines. Typically, a combustion chamber is annular and is fitted around its circumference with a plurality of fuel injector devices that are mounted in circular holes in the end wall. Each device opens out into the combustion chamber at an end referred to as a bowl, having the shape of a bowl that flares in the gas flow direction, while air penetrates continuously into the chamber so as to be mixed with the injected fuel. Since the end wall of the combustion chamber is in the immediate proximity of the injector devices that it carries, it is subjected to high temperatures. An end wall is thus provided around the periphery of each bowl with a deflector for protecting the end wall from high temperatures, typically by creating an insulating layer of air between the deflector and the end wall. In order to improve the insulating ability of this layer of air, it is conventional practice to pierce the deflector and/or the end wall with orifices situated close to the circumference of the bowl, so as to maintain in said layer a flow of cooler air coming from outside the combustion chamber.
In certain combustion chamber configurations, the bowl includes an annular portion having the root of the deflector secured thereto, with the other portion of the deflector being a plane portion perpendicular to the main axis of the bowl, situated downstream from the end wall. However that interface between the annular portion of the bowl and the root of the deflector leads to undesirable heating of the end wall by conduction via the interface.